Jordan wants to create a rectangular border around his classroom bulletin board, and he has $30$ meters of border. Which of these dimensions will give Jordan the largest area? Choose 1 answer: Choose 1 answer: (Choice A) A $12$ meters by $3$ meters (Choice B) B $7$ meters by $8$ meters (Choice C) C $10$ meters by $5$ meters
Solution: Let's find the area of each rectangle to see which one has the largest area. $\text{Area of a rectangle} = \text{width} \times \text{height}$ $10$ meters by $5$ meters $10\text{ m}$ $10\text{ m}$ $$ $5\text{ m}$ $5\text{ m}$ $\text{Area}={10}\text{ m}\times5\text{ m} = 50\text{ square meters}$ $7$ meters by $8$ meters $8\text{ m}$ $8\text{ m}$ $$ $7\text{ m}$ $7\text{ m}$ $\text{Area}={8}\text{ m}\times7\text{ m} = 56\text{ square meters}$ $12$ meters by $3$ meters $12\text{ m}$ $12\text{ m}$ $$ $3\text{ m}$ $3\text{ m}$ $\text{Area}={12}\text{ m}\times3\text{ m} = 36\text{ square meters}$ $56\text{ m}^2 > 50\text{ m}^2> 36\text{ m}^2$ The bulletin board with the dimensions of $8\text{ meters}$ by $7\text{ meters}$ has the largest area.